Electric furnace working with an electric arc or arcs for melting and extraction of metal from ore.



P. KREFTING.

ELECTRIC FURNACE WORKING WITH AN ELECTRIC ARC OR ARCS FOR MELTING ANDEXTRACTION OF METAL FROM ORE.

APPLICATION FILED APR. 3, 1911.

1,097,336, Patented May 19, 1914.

3 SHEETS-SHEET 1.

[fig-I a q 6, I

P. KREFTING.

ELECTRIC FURNACE WORKING WITH AN ELECTRIC ARC OE ARCS FOR MEI-TING ANDEXTRACTION 0E MET-AL FROM ORE.

APPLICATION FILED APR. 3, 1911.

Patented May 19, 1914.

3 $HEET$SHEET 2.

P. KREFTING. I ELECTRIC FURNACE WORKING WITH AN ELECTRIC ARC OE ARCS FORMELTING AND EXTRACTION- or METAL PROM ORE;

APPLICATION FILED APR. 3, 1911.

1,097,336. Patented May 19, 1914.

3 SHEETS-SHEET 3.

lantern-Io summon wonxme WITH AN ELEcTnIe 'Anc onnos FOR EXTRACTION orMETAL FROM can.

UNITED STATES ra ENT OFFICE.

PETER KREITING, or oHnrstrIANIA, NORWAY..

Specification of Letters Patent.

MELTING, AND

- I Patented May-19, 1914.

Application filed April 3 ,1911. Serial No. 618,648.

T all whom it may concern:

Be it known that I, PETER Knnrrmc, a-

subject of the King of Norway, residing at Christiania, Norway, haveinvented certain new and useful- Improvements in Electric FurnacesWorking with an Electric Arc or Arcs for Melting and Extraction of MetalI i from' Ore; and I do hereby declare' that the following is a full,clear, and exact description of the same, reference being had t'otheaccompanying drawings, forming a part hereof' I 4 r The presentinventionrelates. tQ-1I11pIOVG -ments in electric furnaces Working withanelectric are or arcs for melting and extracting metal fromxore;

The'obj'ectfof'the invention is to provide for maintaining apredetermined temperature in the'melting chamber and also means forinsuring the regular. supply of material (charge) into said chamber.With these and .otherobjectsin view. I provide the fur nace with asuperposed shaft for containing the charge of ore andI further provideone (ormore) flue for the escape of the vapors or gases said flue beingprovided with closing means which is adjustable so as to openautomatically ata pressure in the meltingchamber higher than thepressure, which ismost suitable for the process. I. further arrange theshaft with branch passages to supply the material into the meltingchamberfon'both sides of the arc and in each of said passages means areprovided for the propulsion cf the material, and the mouths of saidpassages are provided with nozzles for the distribution of the materialin the chamber.

On the appended drawings are illustrated furnaces constructed'inaccordance with the present invention.

Figurezl is vertical section on line 1-1 in Fig". 3; Fig. 2 is verticalsection on line 2 -2 in Fig 3; Fig. 3 is. horizontalscction on line 33in Fig. 2; Fig. 4'is section of shaft on line lt-din Fig. 1; Fig. 5shows the lower portion. of conveyer with nozzles in section;-

Fig. 6 represents vertical section ofa furnace arranged with threeelectrodes; Fig. 7

is horizontal section of-Fig. 6, Figs. 8 and 9 show the arrangement ofthree electrode pairs and three lines with a central shaft for thecharge. g

A is a furnace, B; and C. the electrodes fed from a suitable source ofcurrent.

m is the sumpand ae is-the 'taphole for drawing off the melted product.

E is the shaft for the ore-charge. lVithin the shaft is a flue (stack) aleading from the top of the melting chamber a suitable distance upthrough the shaft, and from the top of said flue a passage '0 leads tothe outside of the shaft.

The Valveconsists of a plate I) covering the top of the line a, saidplate. being adjusted to open automatically :at a certain. pressure inthe melting cham-- 'ber.;' If the ore under treatment contains volatilemetals the passage 0 is put in communication with a condenser forcollecting ithe metallic vapors. If, the ore does not ;contain suchvolatile metals, the passage 0 fopens into the air or it leads to aplace,

where the gases may be utilized. The shaft I has an outlet 2' foraqueous vapors and the like, Fig. 2. At the bottom the said shaft sdivided in two branches d and c, Fig. 1,

and each of the said branches is divided into three branches f, g and h,Fig. 5,.formor multi-phase current the material must. be introduced inthe middle of themelting chamber and the electrodes are arranged- Ijsingly or in pairs around the. material so as to form a circle of arcs.

Figs. 6 and 7 show an embodiment of myiimproved furnace having threeelee-. trodes B, C, D and, three inclined conveyersk le k introducingthe material into the melting chamber as a thin jet. Forthe collectionof the material the bottom of the furnace is provided with an elevation,which is surrounded by a wall 72, q are passages through which themelting product may run off into the sump m In Figs. 8 and 9 show amodification of my furna e in which I provide three electrode-pairs B,C, D and three fines a o a? arranged outside the. shaft, said ucscommunicating "with a channel a The central shaft is provided with aconveyer.-

The essential feature of the invention the arrangement of the flue forthe escape for extraction of metal. contained in complex ores,consisting of ZnS+PbS'CuS- AgS, but can also be used. for other ores.Through the flue c (Fig. 2) the furnace is in communication with asystem of tubes for the condensation of vaporized zinc and lead.

The effect of-the furnace is dependent on the nature of'thecharge, or in0ther words of the kind of flux which is-added. As such flux'may bementioned peroxid of iron, lime, alumina,'magnesia, feldspar and thelike; as fuel may be used cheap coal, anthracite-coal powder or otherscrap coal. The furnace may as We'll -be used as calcining furnace asformelting the metals from the 'ore. 1

'tially as described.

' the vertical ber.

Having thus fully described my invention, what I claim as new and.desire to secure by'Letters-Patent, is: a

1. An electric furnace comprising'a' closed melting chamber, a verticalchargingshaft above the-chamber, provided ,with a plurality ofextensions with charging apertures, said apertures being normally closedby the charging material, a flue leading from the melting chamberthroughthe. material :being charged, said flue extending through the shaft, anda plurality ofelectrode's extending into the melting chamber substan-2...A n' electric closed melting chamber, a vertical/chargingshaft'above the chamber provided with a plurality of extensions withcharging apertures, said apertures being normally closed by the chargingmaterial, a flue leading from the. melting chamber through the materialbeing charged and a plurality of conveyers located in extensions of thevertical shaft-for charging the material from shaft into the meltingcham furnace comprising a" In testimony whereof I aflix my signature inpresence of two witnesses.

PETER KREFTING;

Witnesses: I

C. ANT. ABnAHAMsnN, H. W. Y1,SCHLYTTER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

' Washingtom-D. C.

